Filter apparatus for purifying fluids



1949- 1.. G. HENDRICKSON FILTER APPARATUS FOR PURIFYING FLUIDS 3 Sheets-Sheet 1 Filed March 5, 1944 fizzezziar Zuls'arfiilzmmsan 1949- L. G. HENDRICKSON FILTER APPARATUS FOR PURIFYING FLUIDS 3 Sheets-Sheet 2 Filed March 3, 1944 iii/5122 01" Zz/iqErEHemr/awm 5' Aug. '30, 1949.

| G; HENDRICKSON FILTER APPARATUS FOR PURIFYING FLUIDS s Sheets-Sheet 5 Filed March 3, 1944 Patented Aug. 30, 1949 UNITED STATES PATENT OFFICE FILTER APPARATUS FOR PURIFYING FLUIDS Luther Glenn Hendrickson, Flin. Flon, Manitoba, Canada, assignor to Hudson Bay Mining and smelting. Co., Limited, Winnipeg, Manitoba, Canada, a corporation of Canada Application March 3, 1944,, Serial No. 524,960

3 Claims. (Cl. 23-2521) This invention relates to a method whereby intimate contact of a fluid. with a solid in. a fine state of sub-division. is: obtained while maintaining the particles. of solid in. a. compact mass, and whereby extraneous. solids suspended in the fluid can be prevented from: becoming associated with the first mentioned solids while carrying out the operation as discussed above; and to an apparatus whereby the above. mentioned operations can be carried out. satisfactorily; and. to an apparatus as mentioned above into which can be introduced the solid in a finely divided state so as to completely fill confined spaces in said apparatus.

In certain cases, it is required to treat solutions with a reagent in the form of small solid particles with a View to removing small amounts of dissolved materialsfrom the solution. An example of this is the removal of dissolved metal impurities from zinc sulphate solutions byprecipitation on zinc dust. This is ordinarily accomplished by agitating the solution with zinc dust. If agitation is violent, the precipitated metals become dissociated from the precipitating metals. A more satisfactory purification can be accomplished by maintaining the particles of solids ina compact mass while treating the liquid.

This invention is a method of, and an apparatus for, obtaining contact of a fluid with a solid in a finely divided state so that the solid remains in a compact mass.

It is apparent that if any material is precipitated from the liquid by the solid, the precipitated material will also be maintained in a compact body with the particlesof solids. In the case of purification of zinc sulphate solutions by agitation with zinc dust, this condition is roughly achieved by agitating veryslowl-y. However, since the contact is not intimate enough, the rate at which the precipitating reaction proceeds is so slow that a long time is required to achieve the desired result.

A further object of this invention then, is to provide for intimatecontact of the fluid with the finely divided solid while maintaining the particles of solid in a compact body by providing for the positive passageof the fluid through the particles of solid filling a space confined, at least partially, by a medium permeable to a fluid.

Zinc sulphate solutions. often contain small amounts of suspended solids of a gelatinous nature. If such solutions were passed through (say) a confined mass: 01. zinc dust, the suspended elatinous solids would coat the zinc dust particles, thereby rendering them inactive.

Another object of. this invention. is: to: prevent extraneous solids suspended in the fluid from becoming associated with the particles of solid by confining the particles of solid with a medium permeable tov a. fluid, but which is impermeable to both the. particles of solid in the compact body and to the extraneous solids. These extraneous solids, often found in. suspension in zinc sulphate solution, would collect on the retaining medium and render it relatively impervious to the solution.

For this reason, an additional object of the invention is to provide for the revseral of the direction of flow of the fluid through the compact mass of solid particles and the retaining media so that the extraneous solids which might blind the confining media will. be carried away from the conmedia by the fluid- An additional object. of this. invention is to provide for the. mechanical introduction of the finely divided reagent. into the space confined by the porous media and the walls of the apparatus by" passing the reagent in as a slurry of. solid particles suspended in water.

To more clearly illustrate the invention, I will describe the. same by reference to the passage of Zinc sulphate solutions through zinc dust, referring to the accompanying drawings showing. one form of apparatus embodying the invention and adapted to carry the novel process into efiect. Although this method and apparatus as. described is ideally suited to the treatment of zinc electrolytes with zincdust, numerous other applications of the. invention will; be apparent to those skilled in the arts.

Briefly" described, the apparatus comprises an assembly of alternately positioned plates and frames,,Wi-th a filter interposed between each side of each frame: and the adjacent plates. The frames and plates have four aligned bores, a first pair serving for supplying a slurry of solid reagent into the spaces Within the frames and for removing the liquid from the slurry once the reagent. is deposited with-in the frames. The lower portions of the inner surfaces or the. frames are provided with grooves covered with screens, the grooves assisting in. the draining of liquid trorn the slurry, and the screens serving to maintain the solids within the frames.

The plates have grooves on each of their faces, and these grooves are connected. to the second pairof bores. The sets 0t grooves on the opposite faces of each plate are connected one to. each of the second pair of bores.v There. is no direct communication betweenv the first set. of bores and. the grooves on the plates, nor between the second set-oi bores. and the spaces within the frames.

In operation, the first set of bores is used for passing a slurry of solid reagent into the spaces within the frames and for draining away the liquid of the slurry to leave a deposit of solid reagent within the frames. The liquid to be treated is then passed into one of the second pair of bores, whence it passes through the grooves on the plate faces lying on one side of the plates, through a filter Where solids in the liquids are kept from contact with the solid reagent, then through the solid reagent, and through the filter on the other side of each frame into the grooves on the other set of plate faces. From these grooves the liquid which has been treated passes to the other bore of the second pair of bores and is then removed from the apparatus.

The connections to the second pair of bores are reversible so that each one can be used either for feeding liquid to the apparatus or for drain, and the reversal of flow so provided is used in cleaning from the filters any solids which are deposited thereon by the treating liquid as it is passed into the beds of solid reagent.

Having thus set forth objects of the invention, reference will now be had to the drawings where- Figure l is a parallel perspective view of the apparatus embodying the invention.

Figure 2 is a parallel perspective view of a frame I8 showing hidden details as dotted lines.

Figure 3 is a parallel perspective view of a plate I2.

Figure 4 is an enlarged parallel perspective view of the corner of a plate I2 carrying the hole 98 of Figure 3, showing hidden details as dotted lines.

Figure 5 is a sectional view of Figure 1 taken horizontally through solution channels 32 and 34.

Figure 6 is a sectional view of a plate taken vertically through the solution channel I83 at VIVI in Figure 5.

Figure 7 is a. sectional view of Figure 1 taken vertically through the filling channels 28 and 38.

Figure 8 is a sectional view of a frame taken vertically so as to bisect it as at VIII-VIII in Figure '7.

Throughout the various views, like parts are designated by like numerals.

Referring to Figure 1, the numeral I8 refers to a rigid supporting structure carrying two horizontal and parallel beams 22. The head plate I6 is bolted securely to this structure at one end. The frames I8 and plates I2 and the butt plate I 4 rest in the bed formed by the supported beams 22 being supported by the lugs 24 and 26 respectively. The bed also carries a suitable closing mechanism 28 shown in the form of a screw extending through the supporting structure by which the plates and frames can be clamped tightly against the head plate IS.

The head plate I 6 carries a piping arrangement which facilitates the operation of the apparatus. The essential features are a pipe 48, carrying a valve 36, for example a plu valve, leading to a hole 28 in the top corner of the head plate I6. In the diametrically opposite corner of head plate I 6 is a similar pipe 42 and valve 38 leading to the hole 38. At each of the other two corners of the head plate I6 are the holes 32 and 34. into which are threaded pipes carrying the twoway valves 48 and 58 respectively, which may be of the plug valve type. One outlet of the two-way valve 48 is connected to the T 48 by the pipe 81 and the other outlet of valve 48 is connected to the T 52 by the elbow and pipe arrangement 5i. Similarly, one outlet of valve 58 is connected to the T 46 by the pipe 49 and the other outlet of valve 58 is connected to the T 52 by the elbow and pipe arrangement 53. The inlet pipe 84 is threaded into the remaining inlet to T 46. Into the remaining inlet to T 52 is threaded pipe 55 which carries the two-way valve 58. The outlet pipes 58 and 58 are threaded into the valve 54 and lead to separate storage tanks.

Figures 2, 5, '7 and 8 show various features of a frame I8. In order to facilitate complete filling of the chamber I8 in the frame with cake, it is convenient that the confining sides I2 and M be inclined, for example as shown in the drawings. The shape of the bottom part of the frame as confined by sides I8 and I6 in Figur 2 can be varied. For example, it might be made rectangular to carry a larger quantity of reagent. The holes 64 in the top corner of the frame I8 open into a large channel 68 leading to the main frame chamber I8. The inside faces of the lower confining sides are provided With grooves which are covered With a porous medium for retaining the reagent. For example, the sides I8 and I6 carry longitudinal grooves 88 which lead to the channel 84. Across the top of the channel 84 and coinciding with the lands between the grooves 88, are bars 82 which form a grid. Covering these grooves and grid is a medium which is permeable to liquids but which would retain the solid reagent particles. For example, a screen I38 of suitable mesh size may be welded to the inside faces of I8 and I6 so as to be supported above the grooves 88 and by grid bars 82, (see Figure 8). The holes 66 open into the channel 84. Holes 68 and 62 at the other two corners of frame I8, extend through and are not connected directly to the frame chamber I8 but form parts of the impure and purified solution conduits.

In an optional construction of frames I8, the channels 84 lead to individually valved exit ports in each frame, and holes 66 are dispensed with. In this optional arrangement the fluid escapes from each frame separately in place of via holes 66, 88, 38 and valve 38, and all the latter are omitted from the construction.

Figures 3, 4, 5, 6 and '7 show various features of a plate I2. The shape of the plates conforms to the shape of the frames. Holes 86 and 88 at the top and bottom of the plate respectively are placed to correspond to holes 64 and 66 respectively and to form parts of the inlet and outlet conduits for the materials connected with the introduction of the reagent into the frame. Grooves are cut in both faces of the plates so as to ensure even distribution of the solution over the face of the plate prior to passage through the reagent. For example 94, 96 and 98 refer to the main grooves on one face and 95, 97 and 99 are the'corresponding grooves on the opposite face. Subsidiary grooves I88 on one face and IN on the other face complete suitable groove arrangements. The holes 98 and 92 extend through the plates and form parts of the impure and purified solution conduits. The groove 94 is connected with the hole 98 by means of the channel I82. It is preferable that channel I82 be beneath the surface of the plate so as to prevent escape of the reagent through to the hole 98. On the other face, channel I83 corresponds to channel I82 and joins hole 92 and groove 95. It will be noticed that the faces of a plate are identical but diametrically opposite about a central vertical axis.

The head plate I5 carries grooves I86, H8 and I I2 as in Figure 5 and the inner face is the same as one side of a plate I2. The groove I86 is conposted.- withthe hole 34103" the channel I is analogous to channel 1-63 "inplate '12. The holes 32 and 34 in headplate 16 are placedin positions corresponding to holes 68 and 82 in frames and to holes 90 and'=92in-platei2 re spectively. Also the holes 28 and '30 in head plate-I6 are placed in positions corresponding-to holes- 64 and 66 iii-frames If! and to helesii'and 88 in plates I2.

Butt plate 14 carriesgr-ooves 318, IZlland 122 as in Figure 5, and the inner face isthe-sameas one face of aplate I2. Thefaces of the head plate I6 and of the butt plate l4 are identical but diametrically opposite about a central vertical axis, A hole I It inlbutt plate I4 isplaced so as to frame In and a butt plate I4.,.;An number of plates andlframes may be placed between the head plate and butt plateas long as plates-and frames are alternated.

Between each plate and frame is placed aperous medium which will retain the reagent and any deleterious solids in the impure solutienbut which is permeable to the solution. For example in Figures 5 and 7, the medium I28 is a suitable grade of filter paper. Holes are punched in the paper at the four corners so as not to cover the holes in the plates and frames. If the retaming medium I28 is a weak filter paper, it is necessary to use supports I26, to prevent tearing the paper. For example, wire screens I26 may be used on both sides of the filter paper. Holes are made in the corners of the screens I26 to correspond to holes in the plates and frames. In order to make the joint solution tight, rubber as at I32 may be vulcanized around the edgecf the screen and around the holes in the screen.

The operation of the apparatus maybe explained by referring to Figures 1, 5 and 7. Consider the plates and frames to be clamped into position with media I28 and supports I26 in position.

The operation of introducing the reagent into the frame chambers I0 may be carried out by first turning the valves 48 and so that the flow of liquid out through holes 32 and 34 is prevented. The valves 36 and 38 are both opened. ,Pipe 46 is connected to a pump which pumps the reagent as a slurry of particles suspended in liquid through pipe 40 and valve 36, through hole 28 and along the conduit formed by holes 64 in frames I II and holes 86 in plates I2, as inFigure 7. From this conduit, the slurry can flow down through channels 68 in frames Ill into frame chambers 10. The solid particles of reagent will settle and be retained by the retaining medium I30 while the liquid passes through the medium I30, flows along grooves 88 and through grid openings into channel 84. Then the liquid flows along the conduit formed by holes 66 in frames I0 and holes 88 in plates I2, out through holes 3|! in head plate I6, through valve 38 and out pipe 42. The slurry continues to flow in until the frame chambers 10 are completely full.

Havin filled the frame chambers, the valves 36 and 38 are closed. Valve 48 is turned so that solution can flow from pipe 44 through T 46 and pipe 31 toihole 32 but so that solution cannot flow mammals-:32 to .l' 62. Valve 5.0 is turnedso that solutionean flowvfrom hole 34 to T 52,-but' not from $315 to hole :34. V

impure solution is pumped from storage through pipelll, through T 46, through pipe 7 into. hole :32 and into the conduit formed by holes fillin'frarnes I3, holes 90 in plates I2'and hole 1 14 in end plate 14. From this conduit the solution flowstbrough the channels I82 in plates I2. into main grooves $4136 and '98 and then fans out across the plate face in grooves Illa, passes through the supports I26and the retaining me,-

128, through the layer of reagent I24, and then-a ain passes .out through the supports I26 and the retainingmedium 128. It .is picked up thegrooves IIH conducted along the grooves 431,35 nd 85, into the channel I83 and to the conduit formed by the holes 92 vin plates I2 and holes thin-frames 10. Then thepurified solution flows throu h hole 34, through valve 56, pipe .53, through ll 52 and to valve 54 which is turn-edoso that the-solution flows through pipe 58 to puri- .fied solution storage.

r l Anysolids which may have been in suspension in the impure solution would be retained bythe media I28 and would in .time prevent the further new of solution. When these solids have built up sufficiently to retard solution flow, the direction of .flowis reversed. This is accomplished by turning the valve 58 so that solution from pipe 44 may enter hole 34 and by turning valve 48 so that purified solution can flow from hole 32 to valve 54. By this means, the solution flows through the layer of reagent I24 and through the media I28 opposite to the previous direction. By this means the layer of solids which may have been built up, will be washed away with solution and will be carried out to valve 54 which is turned so that this cloudy solution flows through pipe 56 to the impure storage tank. These solids are washed away in a short time and when the solution has cleared, valve 54 is turned so that the purified solution flows out pipe 58.

What I claim as my invention is:

1. In a liquid treating apparatus, an assembly of alternate frames and plates having filters therebetween and having at least four continuous bores spaced about the peripheral portions of each frame and plate, the first and second bores being substantially diametrically opposite from each other and the third and fourth bores being substantially diametrically opposite from each other, said frames having grooves on a portion of the inner surface thereof, filter screens covering said grooves, each frame having a passageway providing communication between said first bore and the space Within the frame, each frame also having a passageway from the grooves to the second bore, said plates having at least one groove on each face thereof, the groove on one face communicating through a passageway with the third bore and the groove on the opposite face communicating through a passageway with the fourth bore, there being plate portions preventing communication of said first and second bores with the grooves in the plates, and there being frame portions preventing communication of said third and fourth bores with the space within the frames.

2. In a liquid treating apparatus, the combination set forth in claim 1, said plates and frames being rectangular, said bores being located in the corner portions of the frames and plates.

3. In a. liquid treating apparatus, an assembly 7 of alternate frames and plates having filters therebetween and having at least four continuous bores spaced about the peripheral portions of each frame and plate, the first and second bores being substantially diametrically opposite from each other and the third and fourth bores being substantially diametrically opposite from each other, said frames having grooves on a portion of the inner surface thereof, filter screens covering said grooves, each frame having a' passageway providing communication between said first bore and the space within the frame for admission of a slurry of solid reagents into the space within the frame, each frame also having a passageway from the grooves to the second bore for egress of the liquid of said slurry, said filter screens retaining the solids of the slurry in the space within the frame, said plates having at least one groove on each face thereof, the groove on one face communicating through a passageway with the third bore and the groove on the opposite face communicating through a passageway with the fourth bore, there being plate portions preventing communication of said first and second bores with the grooves in the plates, and there being frame portions preventing communication of said third and fourth cores with the space within the frames, the end members of said assembly comprising plates having grooves only on their inner surfaces, one of said end plates having means for feeding slurry to said first bore and removing liquid from said second bore, as well as feeding and draining connections to said third and fourth bores for a liquid to be treated, whereby the liquid to be treated passes into one of said third and fourth conduits into the plate grooves connected to that conduit and then successively through the adjacent filter, the solid reagents within the frames, another filter, the groove in the adjacent plate facing the solid reagents, and out of the assembly through the other of said third and fourth bores.

LUTHER GLENN HENDRICKSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

